Matching: Match the terms below with their correct
definitions.
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a. | atom | e. | Dalton’s atomic
theory | b. | atomic mass unit | f. | isotopes | c. | atomic mass | g. | nucleus | d. | cathode ray | | | | |
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1.
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Atoms with
the same number of protons but different numbers of neutrons
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2.
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The smallest
particle of an element that retains the properties of that element
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3.
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The weighted
average mass of an element’s isotopes
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4.
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The
center-most part of an atom where the protons and neutrons are contained
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5.
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Equal to
1/12 the mass of a carbon-12 atom
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6.
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Ray of
radiation traveling from the cathode to the anode
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7.
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States that
all matter is composed of atoms
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Multiple Choice: Identify the letter of the choice that best completes the
statement or answers the question.
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8.
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The mass of
an electron is _____. a. | smaller than the mass of a proton. | c. | a tiny fraction of the mass of an atom. | b. | smaller than the mass
of a neutron. | d. | all of the
above. | | | | |
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9.
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One atomic
mass unit is _____. a. | 1/12 the mass of a carbon-12 atom. | b. | 1/16 the mass of an
oxygen-16 atom. | c. | exactly the mass of one proton. | d. | approximately the mass
of one proton plus one neutron. | | |
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10.
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The atomic
mass of an atom is usually not a whole number because it accounts for _____.. a. | only the relative
abundance of the atom’s isotopes. | b. | only the mass of each of the atom’s
isotopes. | c. | the mass of the atom’s electrons. | d. | both the relative
abundance and the mass of each of the atom’s isotopes. | | |
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11.
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An
industrially important element contains 26 electrons and rusts in the presence of air and moisture.
Identify the element. a. | Aluminum | c. | Potassium | b. | Iron | d. | Sodium | | | | |
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12.
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In
the nuclear equation given below, identify the mass number of uranium.
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True/False: Indicate whether the sentence or statement is true or
false.
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13.
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Ancient
philosophers regularly performed controlled experiments.
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14.
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Both
Democritus and Dalton suggested that matter is made up of atoms.
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15.
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Dalton’s atomic theory stated that atoms separate, combine, or rearrange in
chemical reactions.
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16.
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Dalton’s atomic theory stated that matter is mostly empty space.
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17.
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Dalton was
correct in thinking that atoms could not be divided into smaller particles.
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18.
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Dalton’s atomic theory stated that atoms of different elements combine in simple
whole-number ratios to form compounds.
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19.
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The smallest
particle of an element that retains the properties of that element is called an atom.
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20.
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The number
of neutrons in an atom is referred to as its atomic number.
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21.
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The number
of protons in an atom identifies it as an atom of a particular element.
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22.
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In
the notation  , 107 represents the atomic number and 47
represents the mass number of silver.
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23.
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A
proton is a subatomic particle carrying a charge equal to but opposite that of an
electron.
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24.
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Cathode rays are deflected toward a negatively charged plate in an electric
field.
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Completion:
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Use the
periodic table to identify each element described below. To receive credit, please be sure
to enter the name of the element, not just its symbol.
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25.
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atomic
number 65 is ____________________.
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26.
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78 protons
____________________.
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27.
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44 protons
and 44 electrons is ____________________.
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28.
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atomic
number 24 is ____________________.
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Problem
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29.
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Calculate
the atomic mass of the element X. Report a total of four significant figures in your answer.
Then use the periodic table to identify the element.
Isotope | Mass(amu) | Percent
Abundance | #1 | 27.977 | 92.23 | #2 | 28.976 | 4.67 | #3 | 29.974 | 3.10 | | | |
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30.
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Calculate the number of protons, electrons, and neutrons in an atom of the element
mercury with mass number 202 and atomic number 80.
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